Zulip Chat Archive

Stream: Is there code for X?

Topic: OnePoint Homeomorph


Bjørn Kjos-Hanssen (Nov 04 2024 at 22:24):

Is there already code making it quick to prove this simple statement?

import Mathlib

example (X Y : Type*) [TopologicalSpace X] [TopologicalSpace Y]
  (h : Homeomorph X Y):
    Homeomorph (OnePoint X) (OnePoint Y) := by sorry

(More generally, to prove that various operations on topologies are closed under homeomorphism.)

Jireh Loreaux (Nov 05 2024 at 02:37):

It should be pretty easy with docs#OnePoint.equivOfIsEmbeddingOfRangeEq

Bjørn Kjos-Hanssen (Nov 05 2024 at 04:18):

Thanks, got it to work, except I had to assume [T2Space Y] [LocallyCompactSpace Y].

Yury G. Kudryashov (Nov 05 2024 at 06:20):

#18644

Bjørn Kjos-Hanssen (Nov 05 2024 at 07:38):

... and now I don't have to assume that. Thanks!


Last updated: May 02 2025 at 03:31 UTC